Caridina cantonensis Yu, 1938

Tu, Do Van, von Rintelen, Kristina, Klotz, Werner, Hung Anh, Le, Anh Tuan, Tran, Van Dong, Dang, Thi Yen, Phan, Tong Cuong, Nguyen, Ngoc Khac, Hoang, Dang, Phan Doan & von Rintelen, Thomas, 2021, Taxonomy notes and new occurrence data of four species of atyid shrimp (Crustacea: Decapoda: Atyidae) in Vietnam, all described from China, Biodiversity Data Journal 9, pp. 70289-70289 : 70289

Caridina cantonensis Yu, 1938

Caridina cantonensis Yu, 1938: 290, figs. 7-8. [Type locality: Qing’ao Village, Nan’ao County, Guangdong Province, China; neotype designation by Cai and Ng (1999)].

Caridina mutata Cai & Ng, 1999: 1624; figs. 12-13. [Type locality: mountain stream near Fangcheng Town, Fangcheng County, Guangxi Province, China]

Materials

Type status: Other material. Occurrence: catalogNumber: ZMB 30253 ; recordedBy: Do Van Tu; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : island: Cu Lao Cham ; country: Vietnam; countryCode: VN; stateProvince: Quang Nam; county: Hoi An ; locality: Stream near Bai Huong , Cu Lao Cham Island ; decimalLatitude: 15.93944; decimalLongitude: 108.52; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2017-5-9; year: 2017; month: 5; day: 9; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 30309 ; recordedBy: Do Van Tu; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : island: Cu Lao Cham ; country: Vietnam; countryCode: VN; stateProvince: Quang Nam; county: Hoi An ; locality: Stream near on the road to Bai Huong , Cu Lao Cham Island ; decimalLatitude: 15.94417; decimalLongitude: 108.5125; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2017-5-9; year: 2017; month: 5; day: 9; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: OUMNH 201307016 ; recordedBy: Werner & Maria Klotz; disposition: in collection; Taxon: scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Conghua , small stream and trickle ; decimalLatitude: 23.575; decimalLongitude: 113.4374; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2012-4-1; year: 2012; month: 4; day: 1; Record Level: type: PhysicalObject; institutionCode: OUMNH; collectionCode: OUMNH; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 28041 ; recordedBy: Werner Klotz, Yixiong Cai , Chris Lukhaup ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Near Quing Yuan city ; decimalLatitude: 23.56641; decimalLongitude: 113.17765; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2012-4-1; year: 2012; month: 4; day: 1; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 31788 ; recordedBy: Zheng, M.Q. (1989); disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Kau Sai Chau Island, stream at E shore (Stream "B") ; decimalLatitude: 22.3575; decimalLongitude: 114.3186; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2015-5-28; year: 2015; month: 5; day: 28; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 31790 ; recordedBy: Julia Chan , Thomas von Rintelen; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Kau Sai Chau Island, stream at E shore (Stream "A") ; decimalLatitude: 22.359; decimalLongitude: 114.3185; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2015-5-20; year: 2015; month: 5; day: 20; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 31793 ; recordedBy: Julia Chan ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Kau Sai Chau Island, stream at E shore (Stream "C" upstream) ; decimalLatitude: 22.3535; decimalLongitude: 114.3223; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2015-5-28; year: 2015; month: 5; day: 28; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 32144 ; recordedBy: Werner & Maria Klotz; disposition: in collection; Taxon: scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Spring near Lixi Town (near Ying De) ; decimalLatitude: 23.9059; decimalLongitude: 113.2457; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2010-3-18; year: 2010; month: 3; day: 18; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 32145 ; recordedBy: Werner & Maria Klotz; disposition: in collection; Taxon: scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Conghua , small stream and trickle ; decimalLatitude: 23.575; decimalLongitude: 113.4374; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2010-3-21; year: 2010; month: 3; day: 21; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 32146 ; recordedBy: Werner & Maria Klotz; disposition: in collection; Taxon: scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Small mountain stream near Lixi Town (near Ying De) ; decimalLatitude: 23.9067; decimalLongitude: 113.2521; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2010-3-19; year: 2010; month: 3; day: 19; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 32147 ; recordedBy: Werner & Maria Klotz; disposition: in collection; Taxon: scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Small mountain stream near Lixi Town (near Ying De) ; decimalLatitude: 23.9095; decimalLongitude: 113.2597; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2010-3-19; year: 2010; month: 3; day: 19; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 32183 ; recordedBy: Werner Klotz; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Henquin island , Zhuhai , San Die Quan spring ; decimalLatitude: 22.11369; decimalLongitude: 113.50278; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2009-4-5; year: 2009; month: 4; day: 5; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32185 ; recordedBy: Werner Klotz ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Hongkong Island , Lung Hang Stream ; decimalLatitude: 22.4035; decimalLongitude: 114.3209; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2009-4-7; year: 2009; month: 4; day: 7; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32186 ; recordedBy: pet trade; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu, 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; decimalLatitude: 22.38333; decimalLongitude: 114.1; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2009-8-1; year: 2009; month: 8; day: 1; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32192 ; recordedBy: Werner Klotz ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Lantau Island, Stream at Pui O ; decimalLatitude: 22.2485; decimalLongitude: 113.9828; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2009-4-9; year: 2009; month: 4; day: 9; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32195 ; recordedBy: Werner Klotz ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Stream at Ha Miu Tin ; decimalLatitude: 22.5033; decimalLongitude: 114.2643; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2009-4-8; year: 2009; month: 4; day: 8; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32196 ; recordedBy: Werner Klotz ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Stream near Sheung Miu Tin ; decimalLatitude: 22.5023; decimalLongitude: 114.26; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2019-4-8; year: 2019; month: 4; day: 8; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence : catalogNumber: ZMB 32307 ; recordedBy: Andreas Karge ; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: island: Hong Kong; country: China; countryCode: CN; stateProvince: Hong Kong; locality: Tai Mo Shan ; decimalLatitude: 22.409; decimalLongitude: 114.1372; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2010-3-23; year: 2010; month: 3; day: 23; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 29690 ; recordedBy: Chris Lukhaup; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: W of Shenzen (ca. 1h) ; decimalLatitude: 22.74862; decimalLongitude: 114.06034; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2015-4-15; year: 2015; month: 4; day: 15; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZMB 29756 ; recordedBy: Chris Lukhaup; disposition: in collection; Taxon : scientificName: Caridina cantonensis Yu , 1938; kingdom: Animal ; phylum: Arthropoda ; class: Malacostraca ; order: Decapoda ; family: Atyidae ; genus: Caridina ; specificEpithet: cantonensis; taxonRank: Species ; scientificNameAuthorship: Yu , 1938; vernacularName: atyid shrimp; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location : country: China; countryCode: CN; stateProvince: Guangdong; locality: Shenzen city boundary ; decimalLatitude: 22.74929; decimalLongitude: 114.06058; geodeticDatum: WGS84; georeferenceProtocol: GPS; Identification: identifiedBy: Do Van Tu; dateIdentified: 2020; Event: samplingProtocol: hand net; eventDate: 2015-4-15; year: 2015; month: 4; day: 15; Record Level: type: PhysicalObject; institutionCode: ZMB; collectionCode: ZMB; basisOfRecord: PreservedSpecimen

Description

Material examined for description. Caridina cantonensis Yu, 1938: 7 males, cl 3.5-4.1, 4 females, cl 4.0-4.8 (ZMB 30253), Vietnam: Quang Nam Province, Hoi An City, Cu Lao Cham Island, a stream near Bai Huong, 15°56'22''N 108°31'12''E, coll. Do Van Tu, 9 May 2017; 3 males, cl 3.6-4.0, 2 females, cl 4.2-4.4 (ZMB 30309), Vietnam: Quang Nam Province, Hoi An City, Cu Lao Cham Island, a small stream ca. 3 km to Bai Huong, 15°56'39''N 108°30'45'' E, coll. Do Van Tu, 9 May 2017.

Cephalothorax and cephalic appendages. Carapace length 3.5-4.8 mm. Rostrum straight, slightly bent downwards, reaching to middle or the end of second segment of antennular peduncle, 0.38-0.46 (median 0.43) times as long as carapace, rostral formula: 4-5+9-12/3-5 (n = 10), teeth normal (Fig. 2 a). Suborbital angle acute, completely fused with antennal spine; pterygostomian margin rounded (Fig. 2 a). Eyes well developed with globular cornea, anterior end reaching to 0.7 times length of basal segment of antennular peduncle (Fig. 2 a). Antennular peduncle 0.54-0.67 (median 0.60) times as long as carapace; basal segment 1.38-1.83 (median 1.57) times as long as second segment, second segment 1.4-2.0 (median 1.55) times as long as third segment (Fig. 2 b). Stylocerite reaching almost to middle (0.4 times length) of second segment of antennular peduncle (Fig. 2 b). Scaphocerite reaching beyond distal end of antennular peduncle, 3.0-4.0 (median 3.46) times as long as wide (Fig. 2 a, c).

Abdominal somites, telson and uropods. Sixth abdominal somite 0.5-0.6 (median 0.57) times length of carapace, 1.50-2.0 (median 1.67) times as long as fifth abdominal somite, 0.86-1.05 (median 1.0) times length of telson. Telson length 2.1-2.75 (median 2.44) times as long as proximal width, distal margin triangular, terminating in a short median projection, with 5-6 pairs of dorsal spiniform setae and one pair of dorso-subdistal spiniform setae; distal end with 4 pairs of spiniform setae, lateral pair slightly shorter than intermediate pairs (Fig. 2 d). Pre-anal carina low, with few setae, lacking a tooth or spine. Uropodal diaeresis with 18 movable spiniform setae, outermost one slightly shorter than lateral angle (Fig. 2 e).

Pereiopods. Epipod present on first four pereiopods. First pereiopod short, robust, reaching beyond end of basal segment of antennular peduncle; chela 2.0-2.2 (median 2.0) times as long as wide, 1.33-1.67 (median 1.42) times length of carpus; tips of fingers rounded, without hooks; dactylus slightly longer than palm, 1.0-1.1 (median 1.1) times as long as palm in males and shorter than palm, 0.8-0.86 (median 0.83) times as long as palm in females; carpus excavated anteriorly, 1.5-1.88 (median 1.65) times as long as wide, 0.67-0.8 (median 0.8) times length of merus; merus 2.14-3.0 (median 2.5) times as long as wide, longer than ischium (Fig. 3 a). Second pereiopod long, slender, reaching to distal end of antennular peduncle; chela 2.22-2.63 (median 2.42) times as long as wide, 0.66-0.8 (median 0.73) times length of carpus; tips of fingers rounded, without hooks; dactylus 1.22-1.30 (median 1.26) times as long as palm; carpus 4.5-5.3 (median 4.67) times as long as wide, 1.09-1.19 (median 1.14) times as long as merus; merus 4.18-5.0 (median 4.65) times as long as wide, longer than ischium (Fig. 3 b). Third pereiopod slender, reaching beyond end of scaphocerite by its dactylus, terminating in one claw, with four to five accessory spiniform setae on flexor margin, dactylus 2.83-3.6 (median 3.2) times as long as wide (terminal claw and spiniform setae on flexor margin included), propodus 9.0-10.9 (median 9.42) times as long as wide, 3.5-4.47 (median 3.88) times as long as dactylus; carpus 4.25-5.0 (median 4.75) times as long as wide, 0.61-0.67 (median 0.67) times as long as propodus, 0.45-0.63 (median 0.5) times as long as merus; merus 5.71-6.8 (median 6.19) times as long as wide, bearing four strong, movable spiniform setae on posterior margin of outer surface; ischium with one movable spiniform seta (Fig. 3 c). Fifth pereiopod slender, reaching to end of second segment of antennular peduncle, dactylus 3.2-3.6 (median 3.2) times as long as wide (terminal claw and spiniform setae on flexor margin included), terminating in one large claw, with 25-28 spiniform setae on flexor margin; propodus 13.7-14.69 (median 13.71) times as long as wide, 3.13-5.33 (median 5.22) times length of dactylus; carpus 4.2-4.75 (median 4.50) times as long as wide, 0.48-0.56 (median 0.55) times as long as propodus, 0.4-0.51 (median 0.46) times as long as merus; merus 5.45-6.0 (median 6.0) times as long as wide, bearing 3-4 strong, movable spiniform setae on posterior margin of outer surface (Fig. 3 d).

Pleopods. Endopod of male first pleopod extending to 0.6 times length of exopod, rectangular in shape, anterior part folded backwards, 2.0-2.73 (median 2.53) times as long as proximal width, inner margin concave, outer margin concave or slightly straight, rounded distally, long plumose setae on outer and distal margins, medium-length setae on inner margin; with appendix interna exceeding terminal margin of endopod by 0.3 of its length (Fig. 3 e). Appendix masculina of male second pleopod slender, sub-cylindrical, reaching to proximal 0.5 times endopod length, 4.7 times as long as distal width, finger-shaped, slightly widened distally with some short spiniform setae on outer surface and some long spiniform setae on distal surface; appendix interna at middle of appendix masculina, narrow, small, extending about 0.5 times length of appendix masculina (Fig. 3 f).

Colouration. Body yellowish, few irregular small black spots present on ventrolateral parts of carapace and abdominal somites (Fig. 4 ).

Distribution

Cu Lao Cham, in north-central Vietnam (Fig. 1 a). Guangdong, Guangxi and Hong Kong, China ( Liang 2004).

Notes

Dang et al. (1980) recorded C. cantonensis from Chi Lang District, Lang Son Province, North Vietnam, near the border to China. We could neither find this species amongst our samples surrounding this area nor from many survey sites in the mainland of northern Vietnam. Our samples from Lang Son Province are not just a distinct species compared to C. cantonensis , especially in the anterior region of the endopod of male first pleopod (straight vs. folded backwards), but belong to an undescribed species. As this species has not been known from China until now, a description would be out of the focus of this paper. However, we discovered C. cantonensis at Cu Lao Cham Island off the central coast of Vietnam (Fig. 1 a). The population in Vietnam showed no differences when compared to the original description ( Yu 1938) and the later re-descriptions in Cai and Ng (1999) and Liang (2004), except the lower number of spiniform setae on flexor margin of the dactylus of the fifth pereiopod (25-28 vs. 38-45, Fig. 3 c, cf. Yu (1938): fig. 8h). In China, this species is known from Guangdong and Guangxi Provinces and from Hong Kong Island. It is only found in streams and, based on egg-size (Table 1 ), it can be considered as land-locked ( Dudgeon 1987). In our study, this species was only found on one small island in central Vietnam, far from the type locality (Fig. 1). An introduction of this species, for example, along with fish fry from fish farming, cannot be ruled out.

Figures

Figure 4. Live colouration of Caridina cantonensis Yu, 1938, collected on Cu Lao Cham Island, Hoi An City, Quang Nam Province.